[YUNIKORN-20] Support zero resource allocations in the core scheduler

• Type: Improvement
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 0.8
• Target Version: 0.8
• Assignee: Wilfred Spiegelenburg
• Reporter: Wilfred Spiegelenburg
• Created: 04/Mar/20 11:37
• Updated: 17/Mar/22 06:15
• Resolved: 16/Mar/20 20:10

Description

As described in issue #54 the core should allow allocations without a resource linked to it.
K8 has a concept of different QOS pods. The quality of service definition is linked to the way resources are requested by a pod. QOS is equivalent/linked to oversubscription as we know it in YARN.

Allocations that have no resources have a far deeper impact and also affects placement and pre-emption. We need to be able to properly tag and track them in the core scheduler.

A shortcut solution to allow scheduling of BestEffort QOS pods (pods without resource requests) was added to the k8shim via PR apache/incubator-yunikorn-k8shim#52. That change should be rolled back when we support zero resources on a request.

Issue Links

• is related to: YUNIKORN-1126 Add e2e test for best effort pod